prune LM Head for USD (#36695)

* initial commit

* fix

* fix style

* set default to prune

* add tests

* comment

* remove prune flag from generate

* address Joao's comments

* deprecate_kwarg

* add doc

* fix target_vocab_size

* Update src/transformers/generation/candidate_generator.py

Co-authored-by: Joao Gante <joaofranciscocardosogante@gmail.com>

* Update src/transformers/generation/candidate_generator.py

Co-authored-by: Joao Gante <joaofranciscocardosogante@gmail.com>

* Update src/transformers/generation/candidate_generator.py

Co-authored-by: Joao Gante <joaofranciscocardosogante@gmail.com>

* Update src/transformers/generation/candidate_generator.py

Co-authored-by: Joao Gante <joaofranciscocardosogante@gmail.com>

* fix deprecated argument assistant_model_device

---------

Co-authored-by: Joao Gante <joaofranciscocardosogante@gmail.com>
This commit is contained in:
Jonathan Mamou
2025-04-08 18:44:10 +03:00
committed by GitHub
parent 4321b0648c
commit 121f91d36c
3 changed files with 173 additions and 39 deletions

View File

@@ -20,6 +20,7 @@ class TestAssistantToTargetTranslator(unittest.TestCase):
# Create mock tokenizers with predefined vocabularies
self.target_tokenizer = MagicMock()
self.assistant_tokenizer = MagicMock()
self.assistant_model = MagicMock(device=torch_device)
# Define mock vocabularies for the tokenizers
self.target_vocab = {"hello": 0, "world": 1, "foo": 2, "bar": 3}
@@ -27,15 +28,15 @@ class TestAssistantToTargetTranslator(unittest.TestCase):
self.target_tokenizer.get_vocab.return_value = self.target_vocab
self.assistant_tokenizer.get_vocab.return_value = self.assistant_vocab
self.assistant_model_device = torch_device
self.target_vocab_size = 6
# Instantiate the class under test
self.translator = AssistantToTargetTranslator(
target_tokenizer=self.target_tokenizer,
assistant_tokenizer=self.assistant_tokenizer,
assistant_model_device=self.assistant_model_device,
target_vocab_size=self.target_vocab_size,
assistant_model=self.assistant_model,
assistant_prune_lm_head=False,
)
def test_get_assistant_to_target_input_ids(self):
@@ -53,19 +54,19 @@ class TestAssistantToTargetTranslator(unittest.TestCase):
def test_get_target_ids(self):
"""Test the translation of assistant candidate IDs to target candidate IDs."""
assistant_input_ids = torch.LongTensor([[0, 1, 2]]).to(
self.assistant_model_device
self.assistant_model.device
) # 'hello world foo' in assistant tokenizer
target_input_ids = torch.LongTensor([[0, 1, 2]]).to(
self.assistant_model_device
self.assistant_model.device
) # 'hello world foo' in target tokenizer
assistant_candidate_ids = torch.LongTensor([[0, 1, 2, 4]]).to(
self.assistant_model_device
self.assistant_model.device
) # 'hello world foo baz' in assistant tokenizer
expected_target_ids = torch.LongTensor(
[[0, 1, 2, self.translator.SUPPRESS_TOKEN_ID]]
).to(
self.assistant_model_device
self.assistant_model.device
) # 'hello world foo baz' in target tokenizer (baz is mapped to self.translator.suppress_tokens_id since it does not exist in target vocab)
actual_target_ids = self.translator.get_target_ids(
@@ -77,12 +78,12 @@ class TestAssistantToTargetTranslator(unittest.TestCase):
"""Test the conversion of assistant logits to target logits."""
# Assistant logits for IDs 0, 1, 2
assistant_logits = torch.FloatTensor([[[0.1, 0.2, 0.3, 0.4, self.translator.FILTER_VALUE]]]).to(
self.assistant_model_device
self.assistant_model.device
) # Shape (1, 1, 5)
# Expected target logits (target_vocab_size = 4)
expected_target_logits = torch.full((1, 1, self.target_vocab_size), self.translator.FILTER_VALUE).to(
self.assistant_model_device
self.assistant_model.device
)
expected_target_logits[0, 0, 0] = 0.1 # 'hello'
expected_target_logits[0, 0, 1] = 0.2 # 'world'
@@ -119,7 +120,8 @@ class TestAssistantVocabTranslatorCache(unittest.TestCase):
self.assistant_tokenizer = MockTokenizer({"hello": 0, "world": 1, "foo": 2})
self.other_target_tokenizer = MockTokenizer({"foo": 2, "bar": 3})
self.other_assistant_tokenizer = MockTokenizer({"baz": 4, "qux": 5})
self.assistant_model_device = torch_device
self.assistant_model = MagicMock(device=torch_device)
self.target_vocab_size = 6
def test_same_instance_for_same_tokenizers(self):
@@ -127,14 +129,16 @@ class TestAssistantVocabTranslatorCache(unittest.TestCase):
translator1 = AssistantVocabTranslatorCache.get_translator(
self.target_tokenizer,
self.assistant_tokenizer,
assistant_model_device=self.assistant_model_device,
target_vocab_size=self.target_vocab_size,
assistant_model=self.assistant_model,
assistant_prune_lm_head=False,
)
translator2 = AssistantVocabTranslatorCache.get_translator(
self.target_tokenizer,
self.assistant_tokenizer,
assistant_model_device=self.assistant_model_device,
target_vocab_size=self.target_vocab_size,
assistant_model=self.assistant_model,
assistant_prune_lm_head=False,
)
self.assertIs(translator1, translator2, "Translators should be cached and identical")
@@ -143,14 +147,16 @@ class TestAssistantVocabTranslatorCache(unittest.TestCase):
translator1 = AssistantVocabTranslatorCache.get_translator(
self.target_tokenizer,
self.assistant_tokenizer,
assistant_model_device=self.assistant_model_device,
target_vocab_size=self.target_vocab_size,
assistant_model=self.assistant_model,
assistant_prune_lm_head=False,
)
translator2 = AssistantVocabTranslatorCache.get_translator(
self.other_target_tokenizer,
self.other_assistant_tokenizer,
assistant_model_device=self.assistant_model_device,
target_vocab_size=self.target_vocab_size,
assistant_model=self.assistant_model,
assistant_prune_lm_head=False,
)
self.assertIsNot(translator1, translator2, "Translators should differ for different tokenizers")
@@ -164,8 +170,9 @@ class TestAssistantVocabTranslatorCache(unittest.TestCase):
translator = AssistantVocabTranslatorCache.get_translator(
target_tokenizer,
assistant_tokenizer,
assistant_model_device=self.assistant_model_device,
target_vocab_size=self.target_vocab_size,
assistant_model=self.assistant_model,
assistant_prune_lm_head=False,
)
self.assertEqual(len(AssistantVocabTranslatorCache._cache), initial_cache_size + 1)
@@ -192,8 +199,9 @@ class TestAssistantVocabTranslatorCache(unittest.TestCase):
translator = AssistantVocabTranslatorCache.get_translator(
target_tokenizer,
assistant_tokenizer,
assistant_model_device=self.assistant_model_device,
target_vocab_size=self.target_vocab_size,
assistant_model=self.assistant_model,
assistant_prune_lm_head=False,
)
# Create weak references before returning
refs = (weakref.ref(translator), weakref.ref(target_tokenizer), weakref.ref(assistant_tokenizer))
@@ -239,16 +247,18 @@ class TestUniversalSpeculativeDecoding(unittest.TestCase):
self.target_tokenizer.bos_token_id = self.target_tokenizer.eos_token_id
if self.assistant_tokenizer.pad_token_id is None:
self.assistant_tokenizer.pad_token_id = self.assistant_tokenizer.eos_token_id
if self.target_tokenizer.bos_token_id is None:
if self.assistant_tokenizer.bos_token_id is None:
self.assistant_tokenizer.bos_token_id = self.assistant_tokenizer.eos_token_id
self.input_ids = torch.tensor([[1, 2, 3]]).to(torch_device)
self.model_kwargs = {
"attention_mask": torch.ones_like(self.input_ids).to(torch_device),
}
atm_translator = AssistantVocabTranslatorCache.get_translator(
self.target_tokenizer, self.assistant_tokenizer, self.target_config.vocab_size, torch_device
target_tokenizer=self.target_tokenizer,
assistant_tokenizer=self.assistant_tokenizer,
assistant_model=self.assistant_model,
target_vocab_size=self.target_config.vocab_size,
)
self.generator = UniversalSpeculativeDecodingGenerator(
input_ids=self.input_ids,
@@ -286,7 +296,7 @@ class TestUniversalSpeculativeDecoding(unittest.TestCase):
)
input_ids = torch.tensor([[self.target_tokenizer.convert_tokens_to_ids(missing_token)]])
self.generator.input_ids = input_ids
candidates, scores = self.generator.get_candidates(input_ids)
candidates, _ = self.generator.get_candidates(input_ids)
self.assertIsNotNone(candidates)
def test_speculation_depth(self):
@@ -296,7 +306,7 @@ class TestUniversalSpeculativeDecoding(unittest.TestCase):
for depth in [1, 8, 17]:
self.generator.num_assistant_tokens = depth
candidates, scores = self.generator.get_candidates(input_ids)
candidates, _ = self.generator.get_candidates(input_ids)
self.assertLessEqual(candidates.shape[1] - input_ids.shape[1], depth)
def test_device_consistency(self):
@@ -310,10 +320,6 @@ class TestUniversalSpeculativeDecoding(unittest.TestCase):
"""Test that USD matches vanilla sampling with temperature set to nearly 0"""
prompt = "Test text"
pipe_usd = pipeline("text-generation", model=cls.target_name, assistant_model=cls.assistant_name)
pipe_usd_output = pipe_usd(prompt, max_new_tokens=5, do_sample=True, temperature=1e-9) # Nearly 0 temperature
usd_text = pipe_usd_output[0]["generated_text"]
pipe_vanilla = pipeline(
"text-generation",
model=cls.target_name,
@@ -321,5 +327,13 @@ class TestUniversalSpeculativeDecoding(unittest.TestCase):
pipe_vanilla_output = pipe_vanilla(prompt, max_new_tokens=5, do_sample=False)
vanilla_text = pipe_vanilla_output[0]["generated_text"]
pipe_usd = pipeline(
"text-generation",
model=cls.target_name,
assistant_model=cls.assistant_name,
)
pipe_usd_output = pipe_usd(prompt, max_new_tokens=5, do_sample=True, temperature=1e-9) # Nearly 0 temperature
usd_text = pipe_usd_output[0]["generated_text"]
# Assert that the outputs match
cls.assertEqual(usd_text, vanilla_text)